Electronic devices such as smartphones, notebooks, tablet computers, etc. are widely used due to their availability and portability, and are gradually becoming indispensible tools in modern society. Since the electronic devices are designed to be highly portable, family members or friends would often want to watch a movie or taking photographs during gathering sessions using their personal electronic device. Due to the limited screen size of the electronic devices, not only better video effects cannot be obtained, and in order for the users to view a particular screen at the same time, the users need to huddle together in a small space, or the particular electronic device need to be rotated among the users. Although application software are now available to allow multiple electronic devices to form a large screen in parallel, these application software do not hold the electronic devices together. For viewing purpose, the electronic devices need to be placed on the same plane, which is easy for misalignment to occur through accidental touching or sliding the screens of the electronic devices, causing much inconvenience. In addition, since battery power capacity of each of the electronic devices is different, therefore, it often happens that the electronic devices suddenly run out of battery power during usage, or the application software cannot be utilized due to insufficient battery power of the electronic devices.